【作者】 陈生荣；

【导师】 冯平；

【作者基本信息】 天津大学 ， 水利水电工程， 2004， 硕士

【摘要】 摘 要随着水电机组容量和尺寸的不断增大，转速的相应增提高，机组的运行稳定性问题已成为电站机组设计、安装和运行极为关注的问题。本文针对水轮发电机组在运行过程中出现的影响运行稳定性的振动、水压脉动问题进行了阐述，通过目前国内外正在模型或真机上进行的尾水管压力脉动的测试和分析的大量研究，对尾水管中水流引起的低频水压脉动进行了理论分析。并对万家寨电站水轮机尾水管的破坏情况进行分析，提出了相应的改进措施及建议。在水电站机组运行中由于自激振动引起的破坏时有发生，自激振动产生的破坏对不同的机组，其破坏的部位和程度不尽相同。长期以来，在稳定性方面，对安装检修质量问题带来的影响缺乏足够的认识，论文从电站机组安装的角度分析了改善机组运行稳定性，防止或减轻自激振动发生的途径。国内外目前对水电站机组运行稳定性没有统一的评价标准，特别是水轮机尾水管水压脉动，在讨论问题时经常采用?H / H 进行评价。电站运行实践证明：同一?H / H 值，对不同水头的影响是不同的。这就使得?H / H 具有不确定性，因此，文中对机组运行压力脉动的评价进行了讨论和探讨,提出了对评价参数的建议。根据万家寨电站 2#机组的稳定性试验，结合机组设计的运转特性曲线，提出了机组在未完全采取稳定性工程措施前的运行建议及进一步对稳定性研究的方向。稳定性试验前，已对机组进行了动平衡和空载变励磁试验，消除了非水力不稳定定因素。通过对万家寨电站 2#机的现场稳定性测试，及对采集的数据进行的频谱分析，得出了 2#机组振动的主要原因是水力因素作用的结果，提出了消振、减振的措施。更多还原

【Abstract】 With the increase of unit capacity, size and rotational speed of the hydraulicgenerator in the large hydropower station, the problem of hydraulic instability on theFrancis turbo-generator sets has become more and more important during its designand operation. According to the instability problem of the hydraulic turbo-generator set, a greatdeal of research works have been done in the practice measure or the model test aboutthe draft tube pressure of the generator, and the low-frequency pressure-pulse causedby the water flow in the draft tube has been analyzed. Some improving measurementscorrespondingly on the damages of the draft tube have been suggested in Wan jia zhaihydropower station. As the destruction causing by self-vibration often appears, the damage part andlevel are very different in different hydropower generator during its operation. For along period, the understanding of the quality problem of the set installment andmaintenance is much lack at the generator stability. Therefore, the improvingapproach about the stability of the hydraulic generator has been investigated, that canavoid or alleviate the self-vibration of the generator. At present, there are no uniform evaluation standards about the operatingstability of the hydraulic turbo-generator set at home and overseas. Especially thehydraulic pressure-pulse of Francis turbine generator in the draft tube, the value?H / H is usually used to appraise the stability in the practice. It has proved that thesame value of ?H / H has different influence on the different water head during theoperating of hydraulic generator. All these make the value of ?H / H uncertainty.Then, the pressure-pulse of the operating hydropower generator has been discussedand investigated in this paper. According to the above, the usage of the evaluationparameter has been obtained for the operating stability. Based on the tests of the stability about 2# generator in Wan jia zhai hydropowerstation, some suggestion of the stability project hydropower generator has beenproposed. Though the practice measure of the stability in Wan jia zhai hydropower stationand the frequency analysis of the measuring data, the results showed that the vibrationin 2# set mainly was caused by the hydraulic elements. At last, some measurements toeliminating and decreasing the vibration are given.更多还原